Acciona said it acted to help Nordex "navigate the turbulence" in the market following the insolvency of Senvion, as the Spanish energy group bought a €99m ($109m) additional stake in the German wind OEM and launched a takeover offer for the whole business.

Acciona – already the largest shareholder in Nordex – boosted its stake in the company to 36.3% from just below 30%, above the threshold requiring it to launch a full offer.

Confirming that it will now also offer to buy 100% of Nordex at €10.32 per share, Acciona investor relations chief Raimundo Fernández-Cuesta told financial analysts that the global infrastructure and energy group wants to "protect its investment in Nordex".

The extra injection of funds via the capital raise, which came at Nordex's invitation, "should allow the company [Nordex] to navigate the turbulence in the aftermath of Senvion," said the Acciona official, referring to the insolvency of the Germany-based OEM earlier this year.

Acciona is sending a "strong signal to Nordex's clients, suppliers and banks," said Fernández-Cuesta, adding that the developer wants the turbine-maker to remain part of its plans as it develops wind farms around the world.

Papers for the full takeover will be lodged with German regulators, and if the bid is successful the process could be completed in early 2020, he said.

Fernández-Cuesta offered "no comment" when asked whether Acciona expects the €10.32 per share price to be attractive enough. Nordex shares were already trading 8% higher at €10.96 in Frankfurt following news of the offer on Tuesday morning.

Nordex CEO José Luis Blanco welcomed Acciona's "reinforcing its commitment and supporting Nordex with further equity, as its single biggest shareholder.

"We see significant opportunities in the market with our leading products as we continue on our path to profitable growth."

Acciona became the biggest shareholder in Nordex under the deal that saw the latter acquire the Acciona Windpower turbine OEM business in 2016.

Like all OEMs operating in the global wind market, Nordex has found the going tough as growth shifts to new markets and auctions replace government subsidies.

The company is seen as part of a vulnerable group outside the clutch of industry giants such as Vestas, Siemens Gamesa and GE that are tipped to increase their domination of the market.

Although the company stayed loss-making in the first half of 2019, it is bullish on the prospects for its new larger turbines, higher orders and a spike in activity in the second half of the year.